The subject of the present invention is a pipette which comprises a frame portion shaped as a handle, a cylinder being formed inside the frame portion, as well as a piston fitted into the cylinder by means of a seal ring, a piston rod connected to the piston, as well as a press knob with shaft, fitted at the upper end of the frame portion, and that, around the shaft of the press knob, a calibration sleeve is fitted by means of a threaded joint, by means of which calibration sleeve the lower limit of the movement of the piston during pipetting can be determined.
In prior art, numerous pipettes are known that can be calibrated precisely to the desired volume, e.g., the pipettes disclosed in the Finnish Pat. Nos. 57,542 and 57,543. These pipettes, however, involve the drawback that the heat conducted from the operator's hand expands the frame of the pipette, into which the adjusting and calibrating members are fitted, whereby the precision of the adjustment and calibration is no longer reliable.